It has been desirable in recent years to provide improved noise control in earthmoving vehicles without impairing the engine cooling function. Prior art includes Japanese Patent Publication No. 49-40169 dated Oct. 31, 1974 by Kabushiki Kaisha Komatsu Seisakusho and U.S. Pat. No. 4,121,683 issued Oct. 14, 1978 to Y. Kohriyama. These devices have been arranged so that sound and air discharged through the air exhaust opening in the radiator guard are discharged upwardly from a vehicle body by a radiator mask or a radiator silencer attached to the front of the radiator guard, reducing noise at both the front and at the sides of the vehicle body. However, the prior art devices have resulted in increased noise at the level of the upper part of the vehicle body, which may be objectionable when the vehicle is operating in urban or other noise-sensitive areas.
In the prior art devices having the radiator mask or radiator silencer attached to the front of the radiator grille, there is a large opening that leaves the front of the radiator core substantially open. Foreign matter, such as soil, sand, and the like, can impinge on the radiator core by action of the cooling fan during machine operation. This can damage the radiator core or reduce its efficiency by adhering thereto. Another shortcoming of the radiator silencer is that it extends a greater than normal distance from the front of the vehicle body in order to introduce exhaust air smoothly into the upper portion of the vehicle body, thus requiring more space and detracting from the general appearance of the vehicle.